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931.
Ananya CHAKRABORTY M. CHAKRABORTY 《Journal of Transportation Systems Engineering and Information Technology》2010,10(6):53-63
In real world applications the supply, the demand and the transportation cost per unit of the quantities in a transportation problem are hardly specified precisely because of the changing economic and environmental conditions. It is also important that the time required for transportation should be minimum. In this paper a method has been proposed for the minimization of transportation cost as well as time of transportation when the demand, supply and transportation cost per unit of the quantities are fuzzy. The problem is modeled as multi objective linear programming problem with imprecise parameters. Fuzzy parametric programming has been used to handle impreciseness and the resulting multi objective problem has been solved by prioritized goal programming approach. A case study has been made using the proposed approach. 相似文献
932.
Rajiv Ganguly Brian M. Broderick 《Transportation Research Part D: Transport and Environment》2009,14(4):231-239
Different methods for predicting levels of roadside NO2 from NOx concentrations have been proposed. Prior work suggests that either a linear or a logarithmic relationship exists among the roadside NO2 and NOx concentrations. We modify and compare those methods with new formulations based on the principles of the original methods for datasets pertaining to Dublin. A new relationship based on the power law is developed to better model the decay of the ratio of (NO2/NOx)road ratio with increasing NOx concentration. These formulations are compared and examined at two study sites: at an intermittently congested urban street canyon and a free-flowing motorway. 相似文献
933.
Richard G. Hildreth 《Coastal management》2013,41(3):171-191
Abstract Section 8(g) was added to the Outer Continental Shelf Lands Act (OCSLA) in 1978. It mandated sharing of the revenues from tracts that included oil and gas pools underlying the federal‐state boundary 3 miles offshore. Revenues were to be split based on agreements negotiated by the secretary of Interior and the relevant coastal state governor or “fair and equitable”; divisions made by the federal district courts. Only one agreement was concluded. Texas and Louisiana sued to force distribution of their shares of $6.1 billion in 8(g) funds held in escrow. In 1986 Congress divided the escrowed 8(g) revenues approximately 27 percent to the adjacent states and 73 percent to the federal government and legislated the same split for all future 8(g) revenues. This article examines the complex issues that section 8(g), as amended, raises for the management of federal and state submerged lands. Cooperative federal‐state approaches to implementing amended section 8(g) are reviewed. Section 8(g)'s broader implications as the only federal‐state ocean resource, revenue‐sharing mechanism currently in place also are addressed. 相似文献
934.
The new Dutch shipping policy has given rise to high expectation and curiosity in the world of shipping. This, together with the obvious difficulties of an ex-post study of the effectiveness of such innovative policy, has prompted the authors to take an interest in attempting to investigate changes in ownership of the Dutch fleet 2 years after the new policy has been introduced. To do this, a rather new concept of ‘flagging out’ has been adopted, which is interpreted as a process leading to different degrees of ‘foreignness’ in a shipping operation. In this paper, a method to structure is presented, and ownership information, and changes in it are presented, that are essentially based on the theory of stochastic processes. The data used is the Dutch fleet data, which includes information on the nationality of the flag, parent ownership and management over the period 1994–1998. The results yield interesting insights in the shifts in the ownership and operational structure of shipping companies induced by the new policy. In particular, they allow one to establish the origin of new vessels, in which stage of ownership/operation it is most likely that shifts occur, and to determine the relationship between the different stages of the ‘flagging out’ process. These results, thus, enable an evaluation of the areas in which the policy can be expected to yield results. 相似文献
935.
936.
937.
Sibok Lee Raymond A. Krammes John Yen 《Transportation Research Part C: Emerging Technologies》1998,6(5-6)
This paper documents a fuzzy-logic-based incident detection algorithm for signalized urban diamond interchanges. The model is capable of detecting lane-blocking incidents whose effects are manifested by patterns of deterioration in traffic conditions that require adjustments in signal control strategies. As a component of a real-time traffic adaptive control system for signalized diamond interchanges, the algorithm feeds an incident report (i.e., the time, location, and severity of the incident) to the system's optimization manager, which uses that information to determine the appropriate signal control strategy.The performance of the model was studied using a simulation of an actual diamond interchange. The simulation study evaluated the model's performance in terms of detection rate, false alarm rate, and mean time to detect. The model's performance was encouraging, and the fuzzy-logic-based approach is considered promising. 相似文献
938.
介绍淮安三线船闸基坑降排水的方法,并对降水过程中水位监测结果进行分析,同时阐述了降水对周围建筑物影响并对相关处理方法进行探讨。 相似文献
939.
Rachel L. Milford Julian M. Allwood 《Transportation Research Part D: Transport and Environment》2010,15(2):61-72
This paper investigates the CO2 impact of current and future UK rail track and estimates the material, process and transport emissions associated with construction, maintenance and end-of-life activities for designs at high and low traffic loads. Analysis shows that for current track configurations, track with concrete sleepers has the lowest CO2 impact, followed by steel, hardwood and softwood. Several potential future rail track designs have been analysed including embedded rail and double and quadruple-headed rail. All future track designs have a lower impact than current designs, but this improvement is more marked at high traffic loads. Up to a 40% reduction in CO2 impact could be achieved if the UK rail network was to move from conventional track design to a double-headed embedded rail design. Key levers for reducing the CO2 impact of track are identified as service life extension, traffic load reduction and the selection of low impact track designs. 相似文献
940.
为了提升数字化造船的科学性,提出基于知识库的舰船智能化设计系统,采用实体—属性—联系的数学模型进行知识表达建立知识库的层次结构,根据支持度确定多维数据关联与分类规则,针对不同专业设定不同的支持度阈值,提高求解最优性,并以多知识库集成模型数据分析为主体,构建一个综合性能分析系统架构模式。仿真分析数据证明,该系统结合数据挖掘与联机数据分析,实现了综合的决策融合,增强了数据的分析能力。通过该系统将舰船设计研发相关的技术、流程、经验和数据等资源进行有效管理,可以有效提升数字化造船水平。 相似文献